1. Field of the Invention
The present invention relates to a liquid crystal display device, more particularly to a fastening structure of the liquid crystal display device which allows a liquid crystal panel and a back light module to be firmly assembled by engaging a housing with a frame through the fastening structure.
2. Description of the Related Art
Generally, as shown in FIG. 1, a liquid crystal display device 100 mainly includes a liquid crystal panel 102 and a backlight module 202. The liquid crystal display device includes two printed circuit boards 104 and 106 for transferring controlling and driving signals to the liquid crystal panel 102 through the tape carrier packages 108. The backlight module 202 mainly includes a lamp 204, a reflector 206, a light guide plate 208 and an optical film 210. The backlight module 202 is configured to distribute a light from the lamp 204 uniformly over the surface of the liquid crystal panel 102. The liquid crystal display device 100 further includes a metal frame 302 and a plastic housing 304 coupled to each other thereby assembling the liquid crystal panel 102 and the backlight module into the liquid crystal display device 100.
According to one conventional technique, as shown in FIG. 2, the metal frame 302 and the plastic housing 304 may be assembled by a screw 402. However, this conventional method requires an extra cost for the screw and extra time for aligning and screwing.
According to another conventional technique, as shown in FIG. 3, the plastic housing 304 has a rectangular recess 502 and the metal frame 302 has a protrusion portion 504 being inserted into the rectangular recess 502 of the plastic housing 304 thereby engaging with the plastic housing 304. According to the aforementioned structure, the metal frame 302 can be coupled to the plastic housing 304 without any extra fastener. In view of the coordinates defined in FIG. 3, the housing 304 and the frame 302 can retain their relative position in the Z-axis direction, but the housing 304 and the frame 302 can't retain their relative position in the Y-axis direction since the rectangular recess 502 doesn't have any supporting structure for immobilizing the protrusion portion 504 in Y-axis direction.